1. Field of the Invention
The present invention relates to an ultrasound probe, and in particular, an ultrasound probe including a heat collecting portion for collecting heat from a plurality of piezoelectric elements.
2. Description of the Related Art
In the medical field, an ultrasound diagnostic apparatus using an ultrasound image has been put into practical use. In general, this kind of ultrasound diagnostic apparatus generates an ultrasound image by transmitting an ultrasonic beam toward a subject from an ultrasound probe, receiving an ultrasonic echo from the subject, and processing the received signal electrically.
In recent years, a voltage applied to a plurality of piezoelectric elements built in the ultrasound probe and power consumption have increased with the advancement of the ultrasound diagnostic apparatus, and heat generation of the plurality of piezoelectric elements has become a problem. When a plurality of piezoelectric elements generate heat, the heat generated in the plurality of piezoelectric elements is conducted to an acoustic lens through an acoustic matching layer disposed above the piezoelectric elements or the like since the thermal conductivity of a backing member disposed below the piezoelectric elements is low. As a result, the surface temperature of the acoustic lens is increased.
The acoustic lens is located at the distal end of the ultrasound probe and is in direct contact with the human body. For this reason, the surface temperature needs to be suppressed so as not to exceed the upper limit defined, for example, in ISO60601-2-37 from the point of view of safety. Therefore, the driving of a plurality of piezoelectric elements is limited so that the surface of the acoustic lens does not have a high temperature. Specifically, the driving conditions of a plurality of piezoelectric elements, for example, a voltage, a wave number, a driving frequency, and a repetition frequency are limited, and transmission and reception sound pressure is limited. Due to the limitation on the driving conditions of a plurality of piezoelectric elements, the S/N ratio of the ultrasound image obtained by transmitting and receiving ultrasonic waves has been suppressed.
As an ultrasound probe for suppressing the temperature rise of a plurality of piezoelectric elements, for example, an ultrasound probe in which a first backing member as a high attenuation medium is provided immediately below each piezoelectric element and a second backing member as a heat conductor having a high heat conductivity is provided immediately below the groove disposed between the piezoelectric elements has been proposed in JP2007-282743A. Thus, it is possible to suppress the temperature rise of the piezoelectric elements by decelerating the ultrasonic wave using the first backing member while discharging the heat generated in a plurality of piezoelectric elements to the outside using the second backing member.